Cray stopped research ages ago, but they principle has been applied in making standard voltage cells, SQID's and single electron transistors.

The frequency of the "gate" current vs the voltage across the junction is very linear.Building an amplifier where the gain is controlled by gate frequency rather than voltage or current sounds really tricky.

Re: ToothacheTry clove oil or cinnamon stick, both are good topical anesthetics.

Strangely enough, I have a connection between superconduction, and substances that make you do dopey things :-

While working in a hut at the Radio and Space Research Station in the UK in 1970, I had to fill a dewar ( like a vacuum flask ) with liquid helium ( we had a superconducting coil around a crystal at - 269 deg C , to detect a laser beam )

The liquid helium was in a dewar inside another dewar of liquid nitrogen, and to get it into the detactor dewar, I had a bottle of normal helium, to push it up the pipe.

The phone in the hut rang , I had a bottle of helium - well, who could resist it ?

I answered the phone in a chipmunk voice, and it was the Director looking for my team leader ! who needs dope to feel stupid ?